Circuit Design

The circuit which is shown here is too easy circuit. In this circuit IC1 is mounted in a unusual mode. At the time when power resumes, pin 2 of IC1 which is through capacitor C1 is grounded goes low and pin 3 of same IC switches to high. In turn of this pin 4 of IC1 which is a reset pin switches to high state for approximately 10 seconds. When the voltage at C1 reaches to 2/3 of the supplied voltage, capacitor starts discharging and output switches to low, grounding the pin 4 which is a reset pin and hence the fell circuit move out of action.

This tutorial explains how to make your own power supply unit for all your electronics and embedded system experiments. It also has a backup battery which will be used in case of power cuts and a display. 

This capacitor power supply can deliver 12 volt DC and 100 mA current to power low current devices. It is provided with surge protection and is totally isolated from mains supply using two capacitors in the phase and neutral lines. So the connected device is safe even if the phase and neutral lines changes.  Transformer…

The proposed simple electronic spy Bug circuit is basically a high gain amplifier using the IC 741 as the heart of the circuit and also a couple of high gain output transistors. The IC 741 if configured as a non-inverting amplifier which performs the function of a pre-amplifier stage. The gain of this IC 741 preamplifier stage may be varied as desired, using the pot across its input and output pin outs. The gain setting is used to set the sensitivity of the amplifier and is set to maximum so that even low volume speech conversation may be picked through it. The mic at the input transforms sound vibrations into minute electrical pulses, which is further amplified by the IC 741 to suitable levels before applying it to the output amplifier stage consisting of a standard DARLINGTON stage. This Darlington stage is made using a couple of high gain transistors bc107A’s.

In this project a protoype circuit which can switch on the device when the light falls on it. For this I will use LM358 IC which is operational amplifier. I have made the circuit with LDR and few more components. But when I interchange the LDR with photodiode, phototransistor and transistor (L14F1) my circuit works well without changing any other components. Before understanding the circuit which I have developed, first let’s have a look on the components used in the circuit.LM358 consists of two independent, high gain operational amplifiers in one package. Important feature of this IC is that we do not require independent power supply for working of each comparator for wide range of power supply.  LM358 can be used as transducer amplifier, DC gain block etc. 

Many of us have modular kitchen which have chimney to extract smoke out so that smell of smoke will not fill in kitchen and avoids the harmful effects of smoke on furniture and kitchen utensils. But sometimes it happens we forget to switch on the chimney which results in smoke in kitchen and sometimes we forget to off the chimney leading to the wastage of electricity and money. So to solve this problem we have described a circuit which will switch on the fan automatically when smoke reaches to point and off the fan automatically.You can also use this circuit while soldering because as we know solder fumes are not good for health so it will on the fan to extract the smoke present in room leaving smoke free area.

This is a simple shooting game comprising of an infrared pulse emitter and receiver.  There are 8 white leds and one green led which will light up periodically. The player has to shoot at the receiver when the green led lights up. This is a simple beginner’s project and can be used to make more complicated projects like “LASER TAG GAME”.  Infrared gun (transmitter) for this electronic game is built around IC1 timer (NE555) wired as an astable multivibrator with a centre frequency of about 35 kHz. The receiver circuit has 3 main ICs – 2 NE555s (one wired as an astable multivibrator and the other for monostable operation) and 1 CD4017B (decade counter). These circuits can be modified to make “LASER TAG GAME”. Read more to find out how IC555 is used in this circuit and how it works. 

  The simple pulse modulation technique called Pulse Amplitude Modulation (PAM) proved to be more power efficient than the PWM and consumes constant power for individual pulses like PPM. In PAM the amplitude of the individual pulses are varied according to the amplitude of the modulating signals. The PAM modulator and demodulator circuits simple compared…

RGB bulb means bulb made up of three LEDs – RED, GREEN and BLUE. It generates light of many different colours. As we all know RED, GREEN and BLUE are three primary colours and all other colours can be generated by mixing these 3 colours in different amount. So in RGB bulb the intensity of RED, GREEN and BLUE LEDs are varied – means the amount of RED, GREEN and BLUE colours are varied to generate different colour or shade of different colour.The intensity of LED is varied using PWM generated by NE555 IC. NE555 chip generates PWM when it is connected in astable mode. So three NE555 ICs are used to vary the intensity of three LEDs – RED, GREEN and BLUE.     

1.  It is not possible for all the electronic beginners to buy a device which can test all the components as it is highly costly.2.  So for all those peoples “All in one Tester” is a solution.3.  This circuit is quite easy to make and also cost fewer amounts to their pockets.4.  This device can test approximately all the components starting from simple resistors till typical IC’s.5.  With the help of this device it is also easy to check the polarity of components, continuity testing and logic state as      well as multivibrator activity.

In most of the homes the door bells are conventional ding-dong type. Most of us don’t like its sound. Due to mechanical moving parts with spring mechanism its long term durability is questionable. I had also one such door bell in my home. After a period of time its performance deteriorates and one time it becomes completely intolerable because of its noisy irritating sound.The new types of door bells available in market are bird sound door bell. They are costly and even I didn’t like it because of its high frequency and high volume sound output.     

Here I am presenting very interesting project that can be use as a nice show piece or display item with live colours. The desire colour can be set manually from 7 different RGB (Red-Green-Blue) colour combinations. FOC light fountain is a made up of hair like small optical fibre cables bunched togather at one side. When light of different colours is given from that side the entire bunch of fibers look like fountain of light. Such show pieces are readily and easily available in gift article shops or show piece item shops.

This tutorial shows you how to make a phone charger which uses any DC source (AAA/AA/SLA battery) as input and is efficient in terms of power utilization. We’ve been holding onto 7805 regulator IC from a very long time and hence a question may arise as to why we are not using the same this time. Well all these days we didn’t care about the efficiency since it was either a low current application or ones which didn’t run completely on battery but this time it is different. This time our aim is to create a device which runs on battery and needs to be utilizing the battery’s energy efficiently.

This is a very easy circuit . This can be employed in automobiles as a sequential indicate light. This circuit is constructed with the help of two ICs first one is a CMOS timer IC i.e. 555 timer and another one is the decade counter IC i.e. CD4017. In this circuit astable mode of the 555 timer IC is been used to trigger the counter. Also few other discrete components are used in the circuit. 

Our governement has made rules that at night times if any vehicle is approaching from opposite side headlights of our vehicle should be dimmed to avoid focusing of . light on the driver in opposite vehicle inorder to avoid accidents . But, we ignore this which is cause for many accidents at night times. 

In Domestic and industrial applications we use water tanks to store water.  Filling water in tank using water pump is quite common. When water inside the tank is over we have fill it by pumping water using an ac motor and after tank is filled with water we have stop the motor to. This is manual system means turning ON motor when tank is empty and turning it OFF when tank is full is manual. But now it is no more manual. Automatic motor on and off system based on tank water level is already available in market. This system is wired system and connecting circuit and arranging wires and circuit is little bit complex. In this system the biggest drawback is wired connections between control circuit and motor. So we have to use lengthy wires from top of the home to water supply unit and control circuit unit. If we want adapt this system for big building it will become too expensive and too complex. 

The circuit uses the CMOS dual D type flip flop CD4013 which contains two positive-edge triggered flip flop to toggle a load connected through a relay. Now [[wysiwyg_imageupload::]]with the help of a switch you can on the device once pressing it and off the device again using the same switch. In CD4013 each module is further equipped with a group of  pin outs assigned as data, set, reset, clock input and a couple complementary output Q and Q(not) . As we know it has couple of output that change or toggle state as response to trigger applied to input terminals. In this circuit, one is wired in toggle mode while other is not used.  Using this circuit we can easily control AC and DC appliances remotely through inexpensive low voltage cable and a standard push to on switch. This circuit can easily support a cable length of 25 meters.